The document summarizes key topics from Chapter 12 of the Sybex CCNA 640-802 book on wireless networks, including defining WLANs and how they transmit radio frequencies, describing common 802.11 wireless standards, and discussing wireless security features and protocols like SSID, WEP, WPA, and WPA2. It also lists objectives covered in the chapter on IEEE standards, CSMA/CD, 2.4GHz and 5GHz frequency bands, and wireless network topologies of BSS and ESS. The summary concludes by instructing readers to review written labs and questions from the chapter.

1. Sybex CCNA 640-802
Chapter 12: Wireless Networks
Instructor & Todd Lammle

2. Chapter 12 Objectives
The CCNA Topics Covered in this chapter
include:
• What is a WLAN?
• IEEE Standards
• CSMA/CD
• ISM 2.4Ghz channels
• UNII Band
• BSS/ESS
• Wireless Security
2

3. Wireless LAN’s
• Transmitting a signal using the typical
802.11 specifications works a lot like it
does with a basic Ethernet hub: They’re
both two-way forms of communication,
and they both use the same frequency to
both transmit and receive, often referred to
as half-duplex.
• Wireless LANs (WLANs) use radio
frequencies (RFs) that are radiated into
the air from an antenna that creates radio
waves.
3

4. Unlicensed Frequencies
4

5. 802.11 Standards
Here are the most popular standards in use
today:
• 802.11b: 2.4Ghz, maximum bandwidth of
11Mbps
• 802.1g: 2.4Ghz, up to 54Mbps
• 802.11a: 5Ghz, up to 54Mbps
5

6. 802.11b CSMA/CD
6

7. ISM 2.4 Ghz Channels
7

8. UNII 5Ghz Band
8

9. Range Comparisons
9

10. BSS/ESS
10

11. Wireless Security
All Wi-Fi Certified wireless LAN products are
shipped in "open-access" mode, with their
security features turned off.
• SSID, WEP and MAC authentication
• 802.11i
• WPA and WPA 2
11

12. Summary
– Summary
– Open your books and go through all the
written labs and the review questions.
– Review the answers in class.
12